Improved amalgamator



F. G. HESSE.

Amalgamator.

No. 70,839. f Patented Nov. 12g-1867.-

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FREDERICK C.. BESSE, or SAN FRANCISCO, CALIFORNIA. Latas Para: No. 70,839, daad November-12, .1867.

Anursovrn AMALGAMATOR.

TO ALL WHOM IT" MAY CONCERN:

Be it known that I', FREDERICK G. Hasen, of San Francisco, in the county of San Francisco, and State of California, have invented a new and useful Machine for Amal'gamating and Separating Gold and Silver'OI-es; and I do hereby declare that the following is a full, clear, and exact description of the construction and opera-l tion of the same, reference beingl had to the annexed drawings, making a part of this specification, in which- Figure I is a transverse section. y l

Figure II represents four horizontal quarter sections, viz, sections A B, B C, C D, and D E.

Figure III represents a one-half transverse section `to illustrate a modification in the construction.

All amalgamating machines heretofore constructed vand used are mainly dependent on gravity to produce contact between mercury and pulp. In consequence, a large portionof the tine particles of gold escapes, no contact, or too light a contact, having been produced..

The nature of my invention consists in the use of centrifugal action on both mercury and pulp, so as to increase the'acton of gravity, as itwere, one hundred fold or more.

Description. l The machine consists of three main parts, viz,lfIrst, the Arevolving amalgamating cylinder D; second, th

, stationary vessel a; third, the cover C c c.

The revolving cylinder D is provided at its upper end with a narrow ilange, e, Fig. I, projecting inwardly from three-eighth-s to one-half inch. The base of cylinder D is closed, the bottom' connecting with hub H to receive the vertical shaft S. y y I' Cylinder D is enclosed by the stationary vessel a, the upperlend of which contains a ilange to receive the cover C. To thebottom is attached the step for shaft S, and containing` also the discharge opening L, as seen in Figs. I and II.

The cover C consists of two parts, c, and c. The outer cylinder, 0 reaches nearly to the bottom of D,

forming, with thes'ame, a narrow cylindrical or annularrspace, A. The inner cylinder or vessel C c is provided with a flange to connect with a. The funnel-shaped bottom is open near the centre so as to form, with H, the 4circular opening p, Fig.- I. Both cylinders, c, and c, form a cylindrical space, the upper end of which communicates with space o by means of channels b b, Fig. II, section AB. The lower end communicates with A by` means of channels d d, their direction 'being contrary to that offb b. m, r, n, and n, are ribs or wings, attached tc the revolving cylinder D. B represents a bridge,supporting the upper bearing of shaft S. l

. Operation. Let us suppose the machine to be filled with water, and to receive a constant supply into vessel T, equal to the discharge through L. 'Rotary motion, at `the rate of three hundred or more revolutions per minute, being given by means of pulley P to shaft S and cylinder D, the ribs or wings m r a and ni'will impart the same motion to the water, causing it to issue through ldischarge L by virtue of its centrifugalhead. 'This flow will 'take place from through p and h; hence upward in -chamber A, and downward again in space o, as indicated v by the arrows,.Fig. I. Independent of `this action of the water, another current will take place. The water will enter channels b b, ow downward between c,and c, issuing at d d, whence'it will flow upward through A again. This low is caused principally by the diiierence of centrifugal pressure existing at the entrance of channels b 6 and at the point of issue at d d, the centrifugal head resulting, being proportional to the difference of the squares of the distances of said points from the axis of rotation, and to thesquare of the angular velocity. This action is also increased .by the direction of the channels and d, the former causing an increase of headby impulse, the latter by suction. (See arrows, Fig. II, A B and B C.)

Now, it will be seen fromthe above that the quantity of water flowing upward in the lower part of-A is equal to the quantity received in T, but'the quantity flowing through the upper portion of `A is augmented byf. the quantity circulating between c, and c. But since the velocity of ow is directly as the quantity under equal eircumstances,the velocity of the water in the upper part of A can be increased as may be desirable? Now, let

us suppose the vessel D to contain a proper .quantity of mercury. Under the influence of cen'trit'ugal'actionV the mercury will rise until arrested by projection e, and form a paraboloid of revolution, (its inner surface,) its axiscoinciding with the axis of rotation of cylinder D.

If 1', represents thev upper radius of this surface, and lr represents the lower radius near bottom of D, n

the number of revolutions per minute, and h the vertical distance of the planes corresponding to 1', and r, we

have r=1/ 9-,2- h assuming n =300, r,=10 inches, L=8 inches. ,`-r is equal' to about one-fourth ofA .00017 1l an inch, and a se'ction of the paraboloidthrough the axis differs not visibly from a straight line, (shown in blue lines, Fig. I.)

Now, if we feed pulp into T, i-t will follow the current through p, and, aided by centrifugal action, will enter h with the same rotary velocity of the mercury.y It will then follow the upward ilow in A between the surface of mercury and c so that the motion of the particles, relatively to that of the mercury, is simply an upward or vertical motion over its surface, analogous to the ordinary manner of floating pulp over a surface of quicksilver, but differing in one essential point, viz, the force of gravity is increased one hundred fold, more or less. The sume force acting alike on quicksilver, water, and particles, the floating capacity, or the ratio of displaeement'and volume of iloat, remains mathematically the same, but the form or nature of displacement changes essentially. If no other force be present, the molecular attraction, in establishingequilibrium, will cause a Huid mass toassumc a spherical form. Under the rinfluence of gravity, and if resting on a horizontal plane to which the fluid does not adhere, the globule will appearL depressed. Ii more duid is added, the upper and lower surfaces form parallel planes. Any addition of liquid will expand the layer, but not increase its height or thickness. (Figure IV, 1 and 2.) This thickness measures in fact the hydrostatic head, which balances the molecular attraction. If the intensity of gravity be increased, less head or thickness will be required to'.

balance said attraction, 3 and 4. A minute particle of mercury, tarnished to keep it from uniting with mercury, will, under ordinary circumstances, remain isolated and be carried off bythe water; while in the centrifugal Vamalgama-tor, the intensity of gravity being, as it were, increased one hundred fold, it will ilattenout, covering a large area, and unite instantly. 'Experiments have fully borne 'out the correctness of this statement. If a globule of any'substance to which the mercury does not adhere, rests on the surface of mercury, it would, under `the ordinary hydrostatic law, sink until the displacement was equal in weight to that of the body, (see 11,` sup posing the specific gravity of the substance to be one-half vthat of the'mercury.) But the fluid, under the influence of molecular attraction, cannot exist with sharp edges or angles,l as b c d, Figure 1l.` In consequence;

the edges will appear curved, and the actual displacement will be equal to the sum of both, viz, the volume of that portion of the body under the surfaceline a 1i, and the annular depression, (painted in black, 9.) The same .globule will, therefore, rise higher above a b with an increase of the volume of this depression. body of a higher specific gravity than mercury will, therefore, not necessarily sink, but its tendency to float will increase with the volume of mercury displaced by the annular cavity. If the surface of the mercury be tar` nished, a small piece of gold will oat with great ease; -but if the mercury adheres to it, producing amalgamation, no cavity will be formed, and the goldwill readily sink. If the intensity of gravity is increased, the tension produced by molecular attraction producesequilibrium with greater curvature of the rounded edges 1 3 4, or, in other words, the hydrostatic head decreases, as above explained. The ball of substance, Figure 9, will float on mercury under an increase of gravity, acting alike on mercury and body, as appears in 10. In this case the volume of depression is so small that it may be neglected, and the tendency to sink would then depend only on the difference of yspecific gravity. If we consider that the tendency of gold to sinh in mercury is also increased directly with an increase of gravity, it must be clear that free gold, but coatedso as not to amalga mate, will be saved in this machine, using mercury not only as an amalgamating agent, but as a fluid, to separate v under the ordinary hydrostatic law, its specific gravity being between that of gold and the debris.`

To clear the space A of pulp, a powerful current is required on account of' lip e, the particles having a tendency, pnder the action of centrifugal force', to lodge against it, forming a layer which may extend to the very bottom of D. As such a current` would be apt to discharge fine'particles of gold, the same having had no time to reach thesurface of mercury, the secondary current c, and c, as above described, has been introduced. The current between d and c is made strong enough to keep the surface of mercury opposite d free from pulp, (sec Figure V, showing4 the accumulated pulp in red.) The surface of mercury opposite ci being clear, the slightest current will be sufiicient to float the pulp from 'h to d, for the following reasons: rst, the 4resistance of an incompressible liquid is not increased under premura-experiments having been made to that effect, under a pressure of ten atmospheres; second, it may appear as if the upward current in A had to overcome the gravity of the particles, which is not the case, a particle being'balanced or in equilibrium at any point on the surface of mercury. Conceivea tangent plane at any point of the surface of the paraboloid. The normal to this'plane, at point lof contact, will be in the direction. of the resultant of the two forces, viz, gravity and centrifugal force. If the velocity of revolution is changed, the velocity of water between d, and c varies in proportion, but as both the centrifugal force acting on the particle and the resistance to the current increase with the square of the angular velocity, the surface ofthe layer of pulp, Fig. V, will remain the same whatever the speed may be. The pulp, after having b'ecn discharged through A, will befcarricd down, o o, between a and D, and finally discharged through L and pipe g.

Fig. III represents an amalgamator with double action, and requiresno explanation. The machine may also be modified so as to revolve cylinder c, together with D. The cylinder c is left out, and. c, does not contain the openings d. Openings b arc made adjustable by means of a ring-valve. The water is allowed to issue through b b, iiowing into T, and so forth. The water necessary to clear chamber A enters, therefore, at 7i, flowing over the whole surface of mercury-a disadvantage above explained.

The machine described in my'caveat, September, 1866, is constructed on the same principle, but differing in detail. The same machine may be used without mercury for separating rich sulphurets from the debris The action of centrifugal force, in combination withJhe current, and the unavoidable vibration in consequence of the high speed, produce such a result. V The pulp remaining in the machine, Fig.A V, in red, has been found to contain or to consist of the 'richest sulphurets in a. perfect staterof separation. l

What I claim as my invention, and-desire lto secure by Letters Patent, is" p v 1. The narrow, annular amalgamating-chamber A, formed by a revolving cylinder, D, and a-n innercylm der, either stationary or revolving with D, constructed for very highiapeed, .and inrcombination with a. hydraulic device to causes. current of Water to pass through said chamber, for the purpose substantially as described.

2. The use of an extrarcurreut .within the chamber A, for the purpose ofv discharging vpulp without inter fering with the amalgamating-current, substantially as described. l

The manner of producing this current by means of a centrifugal head and guide-b'la.des, substantially .as described.

F. G.- HESSE.

Witnesses:

VHENRY HAIG'HT, SAMrsINrAMs. 

